Tire pressure sensor modules, tire pressure monitoring system, wheel, methods and computer programs for providing information related to a tire pressure

ABSTRACT

A first tire pressure sensor module is configured to provide information related to a pressure of a tire of a vehicle and comprises a pressure sensor configured to determine the information related to the pressure of the tire. The pressure module further includes a controller configured to selectively operate the tire pressure sensor module in an active state and in an inactive state, wherein an energy consumption of the tire pressure sensor module is lower in the inactive state than in the active state. The controller is further configured to control an output of the information related to the pressure of the tire in the active state, and operate the tire pressure sensor module in the inactive state based on determining that information related to a velocity of the tire indicates a velocity above a threshold.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.15/933,759 filed Mar. 23, 2018 which is a continuation of U.S. patentapplication Ser. No. 15/469,862 filed on Mar. 27, 2017, which is adivisional of U.S. patent application Ser. No. 14/802,152 filed on Jul.17, 2015, now U.S. Pat. No. 9,643,460, issued on May 9, 2017, whichclaims priority to German Application No. 102014110184.7, filed on Jul.18, 2014, and incorporated herein by reference in its entirety.

FIELD

Embodiments relate to tire pressure sensor modules, a tire pressuremonitoring system, a wheel, methods and computer programs for providinginformation related to a tire pressure of a wheel of a vehicle.

BACKGROUND

Tire Pressure Monitoring Systems (TPMS) are designed to monitor the airpressure inside of pneumatic tires on various types of vehicles.Therefore pressure sensors are used in the tires and the system mayreport the tire pressure information to the driver of the vehicle.Wireless transmission can be used to transmit information on thepressure data to a centralized receiver component in the vehicle. Such aconfiguration can enable the system to report or signal pressure lossesof the tires to the driver. Some known TPMSs provide localizationinformation on the tire or wheel on top of pressure information so as toindicate to a driver of a vehicle the position of a wheel having apressure loss.

Regulations on TPMS requirements become existent in more and morecountries. Automotive manufacturers therefore tend to provide TPMS asstandard equipment. At least some TPMS are battery powered, where thelifespan of such a battery determines the lifespan of the TPMS. Forexample, some national regulations require the lifespan of a TPMS to beat least seven years, which may render power efficiency to an importantdesign objective for TPMS, especially when further functionalities, suchas additional measurements, are also to be implemented in a TPMS module.

SUMMARY

Embodiments provide pressure modules, a system, a wheel, methods andcomputer programs for providing information related to a tire pressureof a wheel of a vehicle. Embodiments make use of a separation of a TPMSinto two modules, where a first module covers a lower velocity range ofthe tire and a second module covers a higher velocity range of the tire.Operating the modules in active and in inactive states may allowoperating the first module in an energy efficient inactive state above avelocity threshold while the second module may be operated in the activestate above the velocity threshold.

Embodiments provide a first tire pressure sensor module configured toprovide information related to a pressure of a tire of a vehicle. Thefirst tire pressure sensor module comprises a pressure sensor configuredto determine the information related to the pressure of the tire. Thefirst tire pressure sensor module further comprises a controllerconfigured to selectively operate the first pressure module in an activestate and in an inactive state, wherein an energy consumption of thefirst pressure module is lower in the inactive state than in the activestate. The controller is further configured to control an output of theinformation related to the pressure of the tire in the active state. Thecontroller is further configured to operate the first pressure module inthe inactive state based on determining that information related to avelocity of the tire indicates a velocity above a threshold. Embodimentsmay therefore provide a first tire pressure sensor module or TPMSmodule, which can be operated in an energy efficient mode above avelocity threshold, which may enable energy saving or battery lifetimeextension. Such improved energy efficiency may also allow for lowercapacity batteries or smaller sized batteries while keeping an expectedlifespan or lifetime.

In some embodiments the first tire pressure sensor module may further beconfigured for valve mounting or it may be comprised in a valve for thetire. Embodiments may therefore provide an energy efficient valvepressure sensor. The first tire pressure sensor module may furthercomprise a battery. Embodiments may enable an extended battery lifespanor lifetime for a valve mounted pressure module. In further embodimentsthe first tire pressure sensor module may comprise a rechargeable energydevice and a power interface, which is configured to charge therechargeable energy device. Moreover, embodiments may provide a firsttire pressure sensor module, which comprises a rechargeable energydevice, such that a lifespan or lifetime of the tire pressure sensormodule may be further extended through recharging, which may inparticular be advantageous for valve mounted tire pressure sensormodules as its battery may last longer, may be of smaller size and/orlighter weight, respectively. In some embodiments the power interfacemay be configured to be coupled with another or a second pressure sensormodule. The other tire pressure sensor module may then be configured tocharge the rechargeable energy device through the interface. Embodimentsmay enable recharging of a first tire pressure sensor module through asecond tire pressure sensor module.

Embodiments further provide a second tire pressure sensor module, whichis configured to provide information related to a pressure of a tire ofa vehicle. The second tire pressure sensor module comprises a pressuresensor configured to determine the information related to the pressureof the tire. The second tire pressure sensor module further comprises anenergy harvester, which is configured to supply power to the tirepressure sensor module. The second tire pressure sensor module furthercomprises a controller configured to operate the second tire pressuresensor module in an active state and in an inactive state. An energyconsumption of the second tire pressure sensor module is lower in theinactive state than in the active state. The controller is furtherconfigured to control an output of the information related to the tirepressure in the active state. The controller is further configured tooperate the second tire pressure sensor module in the active state basedon determining that information related to a velocity of the tireindicates a velocity above a threshold. Embodiments may provide a tirepressure sensor module, which provides or controls the output ofinformation related to a tire pressure above a velocity threshold of atire and may be operated in an energy efficient mode below saidthreshold.

In some embodiments the second tire pressure sensor module may beconfigured for wall or tread mounting inside the tire. Embodiments mayprovide a tire mounted or in-tire TPMS or tire pressure sensor module,which provides information related to a tire pressure above a velocitythreshold for the tire. In embodiments, the second tire pressure sensormodule may hence use energy generated through the movement ordeformations of the tire and use said energy as a power supply. In someembodiments the second tire pressure sensor module may hence be operatedwithout a battery. In further embodiments the second tire pressuresensor module may further comprise an interface configured to supplypower to another tire pressure sensor module. In other words, the secondtire pressure sensor module may be able to power itself and another tirepressure sensor module when the tire velocity is above the threshold.Embodiments may hence provide an operating mode, in which the system ispower supplied from the motion of the tire above the threshold, suchthat the system is operated without relying on any other permanentenergy supply such as a battery. In some embodiments the second tirepressure sensor module may further comprise a sensor configured todetermine information related to a dynamic driving condition of thevehicle. The second tire pressure sensor module may allow taking furthermeasurements relating to the dynamic driving condition of the tire or avehicle the tire is attached to.

In some embodiments the controller may be further configured todetermine the information related to the dynamic driving condition ofthe vehicle using the sensor when the tire pressure sensor module is inactive state. In other words, above the velocity threshold the secondtire pressure sensor module may allow taking additional measurements,e.g. using power supplied through the motion of the vehicle or tire andpossibly also charging another pressure module. For example, the sensormay be configured to determine information related to at least oneelement of the group of a temperature of the tire, a dynamic behavior ofa contact area of the tire, a shape of the contact area of the tire, apressure distribution of the contact area of the tire, a deformation ofthe contact area of the tire, or an acceleration of the tire.

Embodiments further provide a system for determining information relatedto a pressure of a tire comprising a first tire pressure sensor moduleas described above and a second tire pressure sensor module as describedabove. Embodiments provide a tire pressure monitoring system, whichcomprises a first pressure sensor module at a first location of a tire,and which comprises a second pressure sensor module at a second locationof the tire different from the first location. The second pressuresensor module is powered by an energy harvester. The TPMS system isconfigured to transmit, in a first rotating state of the tire, pressureinformation sensed by the first pressure sensor module to an electroniccontrol unit and, in a second rotating state of the tire, pressureinformation sensed by the second pressure sensor module to theelectronic control unit. In some embodiments the second pressure sensormodule may be powered by an energy harvester. Alternatively oradditionally, the second pressure sensor module may be mounted inside ofthe tire.

Embodiments further provide a wheel for a vehicle comprising a tire anda system for determining information related to a pressure of the tireaccording to the above. In some embodiments the first tire pressuresensor module may be configured to provide information related to a tirepressure in a first lower velocity range of the wheel and the secondtire pressure sensor module may be configured to provide informationrelated to a tire pressure in a second higher velocity range. Inembodiments there may be some overlap of the first and second velocityranges of the tire. Hence, in some embodiments in the lower velocityrange the first tire pressure sensor module may provide the informationrelated to the pressure of the tire and in the second velocity range,where energy may be supplied through an energy harvester using themotion of the tire, the information related to the tire pressure may beprovided by the second tire pressure sensor module. Embodiments mayhence provide a concept or system for determining information related toa tire pressure with improved energy efficiency, or with reduced overallpower need with respect to a battery. In some embodiments the firstvelocity range of the wheel starts at or above zero velocity. In otherwords, a first battery powered tire pressure sensor module may cover alower velocity range between zero or standstill of the tire and avelocity threshold and the second tire pressure sensor module may covera higher velocity range starting at a velocity greater than zero,covering the threshold in case of overlap, and up to the highestvelocities of the tire, the vehicle the tire is attached to,respectively.

Embodiments further provide a method for providing information relatedto a pressure of a tire of a vehicle. The method comprises sensing theinformation related to the pressure of the tire and selectivelyoperating in an active state and in an inactive state. Energyconsumption is lower in the inactive state than in the active state. Themethod further comprises controlling an output of information related tothe tire pressure in the active state. The method further comprisesoperating in the inactive state based on determining that informationrelated to a velocity of the tire indicates a velocity above or below athreshold.

Embodiments further provide a method, which comprises sensing a tirepressure with a first sensor module mounted at a first location of atire, and transmitting first tire pressure information based on thesensing of the tire pressure with the first sensor module to anelectronic control unit at least in a first time interval. The methodfurther comprises operating the first sensor module in an inactive stateat least in a second time interval, and sensing the tire pressure atleast during the second time interval with a second sensor module. Thesecond sensor module is mounted at a second location of the tire,wherein the second location is different from the first location. Themethod further comprises transmitting second tire pressure informationbased on the sensing of the tire pressure with the second sensor moduleto an electronic control unit at least during the second time interval.The second sensor module may be powered by an energy harvester and/orthe second sensor module may be mounted inside of the tire.

Embodiments further provide a computer program having a program code ona non-transitory media for performing, when the computer program isexecuted on a computer or on a processor, a method for providinginformation related to a pressure of a tire of a vehicle, as describedabove. In general, embodiments also provide one or more computerprograms having a program code for performing one or more of the abovedescribed methods, when the computer program is executed on a computer,processor, or programmable hardware component. A further embodiment is acomputer readable storage medium storing instructions which, whenexecuted by a computer, processor, or programmable hardware component,cause the computer to implement one of the methods described herein.

Embodiments further provide a vehicle comprising such a system asdescribed above.

BRIEF DESCRIPTION OF THE DRAWINGS

Some other features or aspects will be described using the followingnon-limiting embodiments of apparatuses and/or methods and/or computerprograms by way of example only, and with reference to the accompanyingfigures, in which

FIG. 1 shows block diagrams of embodiments of a first and a secondpressure sensor module;

FIG. 2 illustrates a view chart on state changes in an embodiment;

FIG. 3 shows an embodiment of a first pressure sensor module for valvemounting;

FIG. 4 shows an embodiment of a second pressure sensor module for tiremounting;

FIG. 5 depicts a flow chart of an embodiment of a method for determininginformation related to a tire pressure; and

FIG. 6 depicts a flow chart of another embodiment of a method.

DETAILED DESCRIPTION

In the following some components will be shown in multiple figures,where consistent reference signs refer to functionally identical orsimilar components. Repetitive descriptions may be avoided forsimplicity purposes. Features or components depicted in dotted lines areoptional.

Accordingly, while example embodiments are capable of variousmodifications and alternative forms, embodiments thereof are shown byway of example in the figures and will herein be described in detail. Itshould be understood, however, that there is no intent to limit exampleembodiments to the particular forms disclosed, but on the contrary,example embodiments are to cover all modifications, equivalents, andalternatives falling within the scope of the invention. Like numbersrefer to like or similar elements throughout the description of thefigures.

As used herein, the term, “or” refers to a non-exclusive or, unlessotherwise indicated (e.g., “or else” or “or in the alternative”).Furthermore, as used herein, words used to describe a relationshipbetween elements should be broadly construed to include a directrelationship or the presence of intervening elements unless otherwiseindicated. For example, when an element is referred to as being“connected” or “coupled” to another element, the element may be directlyconnected or coupled to the other element or intervening elements may bepresent. In contrast, when an element is referred to as being “directlyconnected” or “directly coupled” to another element, there are nointervening elements present. Similarly, words such as “between”,“adjacent”, and the like should be interpreted in a like fashion.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of exampleembodiments. As used herein, the singular forms “a,” “an” and “the” areintended to include the plural forms as well, unless the context clearlyindicates otherwise. It will be further understood that the terms“comprises,” “comprising,” “includes” or “including,” when used herein,specify the presence of stated features, integers, steps, operations,elements or components, but do not preclude the presence or addition ofone or more other features, integers, steps, operations, elements,components or groups thereof.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which example embodiments belong. Itwill be further understood that terms, e.g., those defined in commonlyused dictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art andwill not be interpreted in an idealized or overly formal sense unlessexpressly so defined herein.

FIG. 1 illustrates an embodiment of a first pressure sensor module 10configured to provide information related to a pressure of a tire 30 ofa vehicle. In the following a vehicle can be any vehicle using tires,as, for example, a car, a van, a truck, a bus, a plane, a bike, amotorbike, etc. Although, some embodiments may be exemplified using acar, any other vehicle can be utilized in embodiments. The tire 30 isoutlined as a sketch in FIG. 1. The first tire pressure sensor module 10may be located next to the inner opening of the tire 30, i.e. close to apotential rim of the vehicle. The first tire pressure sensor module 10comprises a pressure sensor 12, which is configured to determine theinformation related to the pressure of the tire 30. The pressure sensor12 may comprise one or more pressure sensing elements, one or morepressure detectors, one or more pressure units, etc. The pressure sensor12 may be configured to determine any signal or information, which maybe analog or digital, related to the pressure of its surrounding, forexample of the tire 30, when the pressure sensor 12 is mounted orcoupled thereto.

The first pressure sensor module 10 comprises a controller 14, which isconfigured to selectively operate the first pressure sensor module 10 inan active state and in an inactive state. An energy consumption of thefirst pressure sensor module 10 is lower in the inactive state than inthe active state. In other words the controller 14 is configured tocontrol the first pressure sensor module 10 and the controller 14 iscoupled with the pressure sensor 12. The controller 14 may hencereceive, control or obtain information related to the tire pressure fromthe pressure sensor 12. The controller 14 is further configured tocontrol an output of the information related to the pressure of the tire30 in the active state. The controller 14 may optionally comprise atransmitter 18, which is exemplified in FIG. 1 as a transmit antenna.The transmitter 18 may be configured to wirelessly transmit informationrelated to the pressure of the tire 30 to, for example, a control unitof a vehicle or service station, for example an Electronic Control Unit(ECU). The transmitter 18 may be implemented as or comprise one or moremodules, devices, or units comprising transmitter or transceivercomponents such as typical transmitter and/or receiver components. Suchcomponents may include one or more components of the group of one ormore transmit and/or receive antennas, one or more transmit and/orreceive loops or coils, one or more low noise amplifiers, one or morepower amplifiers, one or more filters, one or more duplexers ordiplexers, one or more analog-digital and/or digital-analog converters,etc. In embodiments the tire pressure sensor module 10 may beimplemented as TPMS sensor and may be referred to as TPMS sensor ormodule 10.

The tire pressure sensor module 10 may hence wirelessly communicate witha receiver module, located outside the tire 30 or wheel, for example anElectronic Control Unit (ECU) of a vehicle. In the embodiment depictedin FIG. 1 the controller 14 is further configured to control an outputof or determine information related to a velocity of the tire 30. Inembodiments the controller 14 may comprise or be coupled to a sensor,which may, for example in terms of an acceleration sensor, determinesuch information related to the velocity, for example represented by oneor more signals comprising information related to speed, rotationalfrequency, radial or tangential acceleration, etc. of the tire 30. Inembodiments the velocity of the tire may be represented by a rotationalspeed of the tire or wheel, or a speed of the center of the tire (e.g.the speed of the vehicle). The velocity may be obtained, determined ormeasured by means of a sensor, e.g. a tangential or radial accelerationsensor. In some embodiments the information related to the velocity maybe determined using an output signal of an energy harvester. Forexample, the output power or output voltage of an energy harvester maydepend on the rotational speed of the tire 30, a roughness of anunderlying surface, respectively. Hence, a level of an output signal ofan energy harvester may indicate information related to the velocity ofthe tire. The controller 14 may be configured to operate the pressuremodule 10 in the inactive state based on determining that theinformation related to the velocity of the tire indicates a velocityabove a threshold. In some embodiments, the controller 14 may beconfigured to operate the tire pressure sensor module 10 in the inactivestate if the information related to the velocity of the tire indicates avelocity above a threshold. In embodiments a switching to the inactivestate may be carried out when the velocity threshold is exceeded, with apossible delay, respectively.

In some embodiments, when the velocity of the tire 30 reaches a certainthreshold, the controller 14 may switch the first pressure module 10 toan inactive state, which is more energy efficient than the active state.It is to be noted that generally an operating mode or state of a tirepressure module may correspond to an alternation between a state inwhich tire pressure information can be obtained and communicated andanother more energy efficient state, in which no tire pressureinformation is communicated. It is to be noted that in embodiments apressure module may be operated in the active state, in which it may beswitched back an forward between a measurement mode and an energy savingmode such that pressure information is made available on a certain timebasis, e.g. every 10 ms, 20 ms, 50 ms, 100 ms, 200 ms, 500 ms, 1 s, 2 s,5 s, etc. It is to be noted that in some embodiments a switching betweenthe measurement mode and the energy saving mode may still take place inthe inactive state, for example, more rarely than in the active statesuch that the energy consumption in the inactive state becomes lower.

In some embodiments the controller 14 may be configured to wait acertain time period when the threshold is reached or exceeded beforeswitching the first tire pressure sensor module 10 to the inactive stateto assure that the velocity remains above the threshold for the timeperiod. In an embodiment the control module 14 may be configured to waitfor the time period thereby assuring that the velocity has reached orexceeded the threshold for more than the time period and then switch thefirst tire pressure sensor module 10 to the inactive state. As has beenmentioned above the threshold may correspond to a certain output levelof an energy harvester, which is indicative of the velocity of the tire.The inactive state may correspond to a standby state, a dormant state, ahibernation state, etc. In the inactive state the first tire pressuresensor 10 might not be able to provide the information related to thepressure of the tire 30, or more rarely than in the active state. Insome embodiments, a transmitter within the first pressure sensor module10 may be switched to an inactive state such that the tire pressureinformation is no longer transmitted to an ECU. In some embodiments, theindication that the velocity is above a threshold may be combined withother criteria to determine the switching of the first tire pressuresensor module 10 into the inactive state. For example, the first tirepressure sensor module 10 may be switched to the inactive state when thevelocity is continuously above a threshold for a predetermined time.Other criteria may be used for determining the switching of the firsttire pressure sensor module 10 into the inactive state.

In some embodiments the first tire pressure sensor module 10 maycomprise a battery 15 as a power supply, which may be coupled to one ormore components of the first tire pressure sensor module 10. Thepressure module 10 may use energy from said battery 15 during activestate or when the information related to the velocity of the tire 30indicates a velocity below the threshold. In other words power supplyfor the first tire pressure sensor module 10 is provided by the battery15. Two opposing design goals may be taken into account whendimensioning such a battery 15. First, the battery 15 may correspond toa significant cost contributor for the first tire pressure sensor module10 or TPMS module. Furthermore, the battery 15 may correspond to asignificant weight contributor for the first tire pressure sensor module10 or TPMS module. The heavier the first tire pressure sensor module 10or TPMS module the more complex becomes a mounting in the wheel, e.g. ata valve of the wheel. For these reasons a smaller, lighter TPMS moduleor less expensive batteries may be desirable.

Second, a larger battery 15 may provide a longer operational time,lifespan or lifetime of the first tire pressure sensor module 10 or TPMSmodule. Furthermore, exact pressure measurements may consume more energythan less exact ones and additional measurements, e.g. acceleration,temperature, etc. may consume additional energy from the battery 15.From research and development perspective there may be a desire for amore accurate monitoring of the tire parameters, for example, for safetyor comfort reasons. Hence additional measurements, such as measurementswith respect to a dynamic driving condition, may be desirable, but eachadditional measurement may consume additional energy. Therefore, alarger or higher capacity battery 15 may be desirable.

Embodiments may enable a more energy efficient concept for a TPMS. FIG.1 also illustrates an embodiment of the second tire pressure sensormodule 20 or TPMS module. The second tire pressure sensor module 20 isalso configured to provide information related to a pressure of the tire30 of a vehicle. The second pressure module 20 comprises a pressuresensor 22, which is configured to determine the information related tothe pressure of the tire 30. The pressure sensor 22 may be implementedin line with the above described pressure sensor 12. As outlined above,the second tire pressure sensor module 20 further comprises an energyharvester 25 configured to supply power to the tire pressure sensormodule 20.

The second tire pressure sensor module 20 further comprises a controller24, which is configured to operate the second tire pressure sensormodule 20 in an active state and in an inactive state. An energyconsumption of the second tire pressure sensor module 20 is lower in theinactive state than in the active state. The controller 24 may beimplemented in line with the above controller 14 and may as well beconfigured to provide the information related to the tire pressure to acontrol unit of the vehicle or service station, for example, using anoptional transmitter 28 in line with the above. The controller 24 may beconfigured to provide or control an output of the information related tothe tire 30 pressure in the active state and the controller may beconfigured to determine information related to a velocity of the tire30. The controller is configured to operate the tire pressure sensormodule 20 in the active state based on determining that the informationrelated to the velocity of the tire indicates a velocity above athreshold, which may be the same or a different threshold as thethreshold of the first tire pressure sensor module 10.

As it is implied by FIG. 1 the first tire pressure sensor module 10 maybe configured for valve mounting or being comprised in a valve of thetire 30. The second tire pressure sensor module 20 may be configured forwall or tread mounting inside the tire 30. The second tire pressuresensor module may comprise an energy harvester 25 configured to supplypower to the second tire pressure sensor module 25 or TPMS module. Thesecond tire pressure sensor module 20 may be equipped with an energyharvester or a nano generator and may be a battery-free TPMS sensor,which converts mechanical energy of the pulse when the TPMS sensor hitsthe ground into an electrical signal from which energy and otherinformation may be determined, for example, information on a rotationalfrequency of the wheel can be determined. In further embodiments thesecond tire pressure sensor module 20 may use an acceleration or shocksensor to determine the information on the rotational frequency of thewheel, e.g. by making use of gravity.

The second tire pressure sensor module 20 may be mounted inside the tire30 and may use the energy harvester 25 as power supply. For example, theenergy harvester 25 may be mounted inside the tire on the backside of acontact area of the tire 30. The surface of the tire 30 is exposed todeformations at the contact area with the underground, e.g. it iscompressed when entering the contact area and decompressed when exitingthe contact area. These deformations are also existing on the inside ofthe tire. The energy harvester 25 may convert this mechanical energyinto electrical energy, which is then used to power supply the secondpressure module 20. For example, the energy harvester 25 may comprise apiezoelectric element to convert the mechanical energy into theelectrical energy. At higher velocities the energy harvester 25 mayprovide enough energy to carry out further measurements, as will bedetailed subsequently. However, if the velocity of the tire 30 is ratherlow for certain periods of time, then not enough energy may be availablefrom the harvester 25, which may, for example, occur in a stop-and-gosection in downtown traffic or when starting the vehicle after a periodof standstill. As regulations might not allow longer periods withoutpressure measurements, they may set certain restrictions on the timeperiod during which a failure has to be indicated, respectively, aconcept based on an energy harvester alone could be seen critical. Theenergy harvester 25 may comprise another source of energy, which howevercontributes to costs, weight, and fragility of the harvester, inparticular when mounted on the inside of the contact area.

If an energy harvester is equipped with an additional energy source,e.g. a battery or accumulator, additional components or circuits may benecessary to provide switching, charging or controlling functionalityfor the energy sources and, for example, for stabilizing the supplyvoltage. Such additional components may consume further space and mayfurther contribute to the costs. Space could be seen as another criticalfactor for an in-tire module, as the larger such a module, the higherare forces exerted by compression and decompression of the contact areaas well as centrifugal forces. Moreover, an energy harvester might notcomply with the needs for a valve mountable pressure module, as weightand room requirement for valve mounting would demand limited forceexerted onto the valve. Such room would be available on the inside ofthe tire 30, but stresses and strain are high such that it may bepreferred not to use large electronic circuits and/or batteries in suchareas.

Embodiments may provide a combination of both of these concepts, wherepressure modules are used for different velocity ranges. FIG. 1 furtherillustrates an embodiment of a system 40 for determining informationrelated to a pressure of a tire 30. The system 40 comprises the firsttire pressure sensor module 10 and the second tire pressure sensormodule 20. The system 40 combines the two tire pressure sensor modules10 and 20. The combination may provide information related to the tirepressure in almost all or all driving conditions and may even allow foradditional measurements, for example, relating to the driving dynamicsof the vehicle at higher velocities. Another embodiment is a wheel for avehicle comprising a tire 30 and a system 40 for determining informationrelated to a pressure of the tire 30.

The state switching is further depicted in FIG. 2. FIG. 2 illustrates aview chart on state changes in the embodiment of the system 40 asdepicted in FIG. 1. The view chart shows the velocity of the tire 30 onthe abscissa and the respective operational state on the ordinate. Ascan be seen from FIG. 2, at zero velocity the first tire pressure sensormodule 10 is active (solid line) and the second tire pressure sensormodule 20 is inactive (broken line). At a first threshold Thr1 thesecond tire pressure sensor module 20 is activated and changes to activestate. It can be assumed that at Thr1 the energy harvester 25 providessufficient energy for the second tire pressure sensor module 20 toreliably sense the tire pressure and provide the information on the tirepressure. At the second threshold Thr2 the first tire pressure sensormodule 10 changes from active state to inactive state and battery powercan be saved at velocities higher than Thr2. It is to be noted that FIG.2 shows some overlap between Thr1 and Thr2 in which both pressuremodules 10 and 20 are in active state, which is an example. Such abehavior may be used when there is not further link, coupling orcommunication between the two modules 10 and 20 and an overlap mayassure that there is always at least one pressure module 10 or 20active. Furthermore, an overlapping regime in which both pressuremodules 10 and 20 are operating concurrently may be used for evaluatingthe sensed pressure information from both pressure modules in order tocheck whether both pressure modules are functioning correctly. Thus, thetwo pressure modules may be used to enhance functional safety for thetire pressure monitoring.

As outlined above. a link, coupling or communication between the twomodules 10 and 20 may be provided, e.g. by means of communicatingcontrollers 14 and 24, by means of a common controller, respectively,there may as well be only a single threshold still assuring that onemodule 10 or 20 is active at any velocity. Moreover, it is alsoconceivable that in some embodiments a small gap is tolerated, i.e.certain velocities at which both modules 10 and 20 are inactive.

In the embodiment illustrated by FIG. 2 the first tire pressure sensormodule 10 is configured to provide information related to a tirepressure in a first lower velocity range 0-Thr2 of the wheel and thesecond tire pressure sensor module 20 is configured to provideinformation related to a tire pressure in a second higher velocity rangeThr1-maximum velocity of the vehicle or even above. As shown in FIG. 2the first velocity range of the wheel starts at or above zero velocity,hence, the first tire pressure sensor module 10 may be used after astandstill of the vehicle. It is to be noted that the first tirepressure sensor module 10 may be operated in the inactive state if thevelocity of the tire equals zero for a certain time period. In otherwords, in embodiments the first tire pressure sensor module 10 might notstay in active state when the vehicle is parked. For example, thecontroller 14 may be configured to operate the first tire pressuresensor module 10 in inactive state based on determining that theinformation related to the velocity of the tire indicates zero velocityfor a certain time-out period. The controller 14 may further beconfigured to operate the first tire pressure sensor module 10 in activestate again, once the tire starts moving or when the information relatedto the velocity of the tire indicates a velocity greater than zero. Forexample, the controller 14 may transit the tire pressure sensor module10 to active state if the velocity of the tire is slightly above zero,e.g. at zero+. The system 40 may combine a valve mounted tire pressuresensor module 10 with an in-tire pressure sensor module. Informationrelated to tire pressure may be provided at any velocity.

FIGS. 1 and 2 illustrate a tire pressure monitoring system 40, whichcomprises a first pressure sensor module 10 at a first location of atire 30, e.g. at the valve or rim. The tire pressure monitoring system40 further comprises a second pressure sensor module 20 at a secondlocation of the tire 30 different from the first location, e.g. in thetire 30. The second pressure sensor module 20 is powered by an energyharvester 25. The tire pressure monitoring system 40 is configured totransmit, in a first rotating state of the tire 30, pressure informationsensed by the first pressure sensor module 10 to an electronic controlunit and, in a second rotating state of the tire 30, pressureinformation sensed by the second pressure sensor module 20 to theelectronic control unit. Another embodiment is a wheel 60 for a vehiclecomprising a tire 30 and a system 40 for determining information relatedto a pressure of the tire 30. In line with the above, the first pressuresensor module 10 may be configured to provide information related to atire pressure in a first lower velocity range of the wheel 60 and thesecond pressure sensor module 20 may be configured to provideinformation related to a tire pressure in a second higher velocityrange. The first velocity range of the wheel may start at or above zerovelocity.

As further shown in FIG. 1 the second tire pressure sensor module 20 mayoptionally further comprise a sensor 28, which is configured todetermine information related to a dynamic driving condition of thevehicle. Such information may as well be provided when the second tirepressure sensor module 20 is in active state. In other words, in anotherembodiment the controller 24 is further configured to determine theinformation related to the dynamic driving condition of the vehicleusing the sensor 28, when the second tire pressure sensor module 20 isin active state. The sensor 28 may be configured to determineinformation related to at least one element of the group of atemperature of the tire, a dynamic behavior of a contact area of thetire, a shape of the contact area of the tire, a pressure distributionof the contact area of the tire, a deformation of the contact area ofthe tire, or an acceleration of the tire.

Embodiments may provide improved system efficiency by operating the twosystems in improved or optimized areas of operation. From a standstillof the vehicle up to a threshold the first tire pressure sensor module10, which may correspond to a valve mounted pressure module, providesthe information related to the tire pressure. As the first tire pressuresensor module 10 is inactive above the threshold a smaller battery maybe used, the lifespan extended, respectively. Above the threshold theenergy harvester 25 provides enough energy to operate the second tirepressure sensor module 20, which may correspond to an in-tire module.Additionally, the second tire pressure sensor module 20 may carry outfurther measurements and provide information related thereto by means ofthe controller 24. If the velocity decreases below the threshold thefirst tire pressure sensor module 10 may take over again.

FIG. 3 shows an embodiment of a first tire pressure sensor module 10 forvalve mounting. FIG. 3 shows on the left hand side a valve 50, whichcomprises a first tire pressure sensor module 10. FIG. 3 illustrates thepressure sensor 12, the controller 14 and the battery 15. On the righthand side FIG. 3 shows a wheel 60 with a rim 70 and a tire 30. The firsttire pressure sensor module 10 is mounted on the rim together with thevalve 50 as shown on the left hand side. In a conventional configurationthe battery may consume about 50% of the room of such a module and maymake up about 50% of its weight. Embodiments may allow using the firsttire pressure sensor module 10 only partially during a drive at lowervelocities, e.g. only when the vehicle moves slower than 20 km/h, whichallows for a corresponding size and weight reduction of the battery.

Furthermore, a series of pressure measurements may be carried out inorder to statistically compensate for pressure variations (average outpressure variations) occurring in the tire. These pressure variationsmay occur due to strikes and hits the tire takes from the underground,which increase with increasing speed of the vehicle. At lower velocitieslower variations can be expected, such that even further energy may besaved in embodiments. Assuming that a vehicle spends 50% in each of thevelocity range sections as depicted in FIG. 2 (50% first pressure module10 only, 50% second pressure module 20 only, Thr1=Thr2—no overlap) thebattery 15 capacity could be also reduced by 50% without lowering thelifetime of the first pressure module 10. A smaller battery may enable asmaller and lighter weight overall pressure module 10 design, which mayin turn enable a less complex mounting at/with the valve 50. The overallcosts for the first pressure module 10 may be decreased. In otherembodiments, the battery 15 size may be left unchanged but the lifetimeor lifespan of the first pressure module 10 may be increased to 15 to 20years, which would correlate to an average expected lifetime or lifespan of a vehicle.

FIG. 4 shows an embodiment of a second tire pressure sensor module 20for in-tire mounting. FIG. 4 shows on the right hand side a part of atire 30, which comprises the second tire pressure sensor module 20. Onthe left hand side, FIG. 4 depicts a magnification of the second tirepressure sensor module 20 which has a circular shape and includes apiezo element as energy harvester 25. When the second tire pressuresensor module 20 is operated at higher velocities, the energy harvester25 can provide sufficient energy such that electronic circuits foroperating the second tire pressure sensor module 20 may be kept at alower complexity and size. In some embodiments an output power or outputsignal level of the energy harvester 25 may be monitored to assuresufficient energy is provided by the energy harvester 25. For example,state switching may be carried out dependent on a sufficient outputpower or signal level of the energy harvester 25. TPMS functionalityabove the velocity threshold may therefore be assured. If the velocityrises even further, more energy may be available than necessary for theTPMS operation. The additional energy may be used for furthermeasurements relating to the driving dynamic condition of the tire 30,the wheel 60 or the vehicle, respectively. For example, temperature oracceleration measurements of the tire may be carried out. Moreover,measurements on the contact area (position, stress, strain, pressuredistribution, deformation) may be carried out. For example, informationrelated to deformation and position of the contact area and to thepressure distribution may be used to further improve comfort and safetyof the vehicle. Such data or information may be measured, pre-processedor processed, and then also provided to a control unit of the vehicle,e.g. by wireless transmission. Such data may especially be useful athigher velocities of the vehicle, which in a synergetic mannercorrelates with the energy exploitation of the energy harvester 25.

Moreover, embodiments of the system 40 may use a modular structure andthe first tire pressure sensor module 10 (e.g. as valve mountedembodiment) may be kept similar for a number of vehicles or vehicleconfigurations. The second tire pressure sensor module 20 may be adaptedto a demand at different vehicles or vehicle configurations, forexample, in terms of the kind of energy harvester 25, in terms of thecontroller 24 or micro controller 24, interfaces, etc.

As shown in FIG. 1 the first and second tire pressure sensor modules 10and 20 may optionally comprise interfaces 16 and 26, through which theymay be coupled. In other words, the first tire pressure sensor module 10may further comprise a rechargeable energy device and a power interface16, which is configured to charge the rechargeable energy device. Therechargeable energy device may correspond to an accumulator, acapacitor, etc. The power interface 16 may be configured to be coupledwith the second tire pressure sensor module 20 and the second tirepressure sensor module 20 may be configured to charge the rechargeableenergy device through the interface 16. The second tire pressure sensormodule 20 then further comprises the interface 26, which is configuredto supply power to the first tire pressure sensor module 10. Such aninterface 16, 26 may correspond to any wireless or wired interface,which allows for such power supply. In some further embodiments theinterfaces 16 and 26 may further allow for communicating informationbetween the controllers 14 and 24, for example, to enable a coordinationof the velocity thresholds or operating states.

FIG. 5 shows a flow chart of an embodiment of a method for determininginformation related to a tire pressure. The method comprises determining80 the information related to the pressure of the tire. The methodfurther comprises selectively operating 82 in an active state and in aninactive state, wherein energy consumption is lower in the inactivestate than in the active state. The method further comprisingcontrolling 84 an output of the information related to the tire pressurein the active state. The method further comprises operating 86 in theinactive state based on determining that information related to avelocity of the tire indicates a velocity above or below a threshold.

FIG. 6 depicts a flow chart of another embodiment of a method. Themethod comprises sensing 90 a tire pressure with a first sensor module10 mounted at a first location of a tire 30. The method furthercomprises transmitting 92 first tire pressure information based on thesensing 90 of the tire pressure with the first sensor module 10 to anelectronic control unit at least in a first time interval. The methodfurther comprises operating 94 the first sensor module 10 in an inactivestate at least in a second time interval and sensing 96 the tirepressure at least during the second time interval with a second sensormodule 20. The second sensor module 20 is mounted at a second locationof the tire 30 and the second location is different from the firstlocation. The method further comprises transmitting 98 second tirepressure information based on the sensing 96 of the tire pressure withthe second sensor module 20 to an electronic control unit at leastduring the second time interval. In line with the above, the secondsensor module 20 may be powered by an energy harvester and/or the secondsensor module 20 may be mounted inside of the tire 30.

Another embodiment is a computer program having a program code on anon-transitory media for performing, when the computer program isexecuted on a computer or on a processor, the above method for providinginformation related to a pressure of a tire of a vehicle.

A further embodiment is a computer readable storage medium storinginstructions which, when executed by a computer, cause the computer toimplement one of the methods described herein. Other embodiments are acomputer program or a computer program product having a program code forperforming anyone of the above described methods, when the computerprogram or computer program product is executed on a processor,computer, or programmable hardware.

A person of skill in the art would readily recognize that steps ofvarious above-described methods may be performed by programmedcomputers. Herein, some embodiments are also intended to cover programstorage devices, e.g., digital data storage media, which are machine orcomputer readable and encode machine-executable or computer-executableprograms of instructions, wherein said instructions perform some or allof the steps of said above-described methods. The program storagedevices may be, e.g., digital memories, magnetic storage media such asmagnetic disks and magnetic tapes, hard drives, or optically readabledigital data storage media. The embodiments are also intended to covercomputers programmed to perform said steps of the above-describedmethods or (field) programmable logic arrays ((F)PLAs) or (field)programmable gate arrays ((F)PGAs), programmed to perform said steps ofthe above-described methods.

The description and drawings merely illustrate the principles of theinvention. It will thus be appreciated that those skilled in the artwill be able to devise various arrangements that, although notexplicitly described or shown herein, embody the principles of theinvention and are included within its spirit and scope. Furthermore, allexamples recited herein are principally intended expressly to be onlyfor pedagogical purposes to aid the reader in understanding theprinciples of the invention and the concepts contributed by theinventor(s) to furthering the art, and are to be construed as beingwithout limitation to such specifically recited examples and conditions.Moreover, all statements herein reciting principles, aspects, andembodiments of the invention, as well as specific examples thereof, areintended to encompass equivalents thereof.

Functional blocks denoted as “means for . . . ” (performing a certainfunction) shall be understood as functional blocks comprising circuitrythat is adapted for performing or to perform a certain function,respectively. Hence, a “means for s.th.” may as well be understood as a“means being adapted or suited for s.th.”. A means being adapted forperforming a certain function does, hence, not imply that such meansnecessarily is performing said function (at a given time instant).

The functions of the various elements shown in the Figures, includingany functional blocks labeled as “means”, may be provided through theuse of dedicated hardware, such as “a processor”, “a sensor”, “acontroller” etc. as well as hardware capable of executing software inassociation with appropriate software. When provided by a processor, thefunctions may be provided by a single dedicated processor, by a singleshared processor, or by a plurality of individual processors, some ofwhich may be shared. Moreover, explicit use of the term “processor” or“controller” should not be construed to refer exclusively to hardwarecapable of executing software, and may implicitly include, withoutlimitation, digital signal processor (DSP) hardware, network processor,application specific integrated circuit (ASIC), field programmable gatearray (FPGA), read only memory (ROM) for storing software, random accessmemory (RAM), and non-volatile storage. Other hardware, conventionaland/or custom, may also be included. Similarly, any switches shown inthe Figures are conceptual only. Their function may be carried outthrough the operation of program logic, through dedicated logic, throughthe interaction of program control and dedicated logic, or evenmanually, the particular technique being selectable by the implementeras more specifically understood from the context.

It should be appreciated by those skilled in the art that any blockdiagrams herein represent conceptual views of illustrative circuitryembodying the principles of the invention. Similarly, it will beappreciated that any flow charts, flow diagrams, state transitiondiagrams, pseudo code, and the like represent various processes whichmay be substantially represented in computer readable medium and soexecuted by a computer or processor, whether or not such computer orprocessor is explicitly shown.

Furthermore, the following claims are hereby incorporated into theDetailed Description, where each claim may stand on its own as aseparate embodiment. While each claim may stand on its own as a separateembodiment, it is to be noted that—although a dependent claim may referin the claims to a specific combination with one or more otherclaims—other embodiments may also include a combination of the dependentclaim with the subject matter of each other dependent claim. Suchcombinations are proposed herein unless it is stated that a specificcombination is not intended. Furthermore, it is intended to include alsofeatures of a claim to any other independent claim even if this claim isnot directly made dependent to the independent claim.

It is further to be noted that methods disclosed in the specification orin the claims may be implemented by a device having means for performingeach of the respective steps of these methods.

Further, it is to be understood that the disclosure of multiple steps orfunctions disclosed in the specification or claims may not be construedas to be within the specific order. Therefore, the disclosure ofmultiple steps or functions will not limit these to a particular orderunless such steps or functions are not interchangeable for technicalreasons.

Furthermore, in some embodiments a single step may include or may bebroken into multiple substeps. Such substeps may be included and part ofthe disclosure of this single step unless explicitly excluded.

What is claimed is:
 1. A tire pressure sensor module, comprising: apressure sensor configured to determine information related to apressure of a tire; a controller configured to selectively operate thetire pressure sensor module in an active state and in an inactive state,wherein an energy consumption of the tire pressure sensor module islower in the inactive state than in the active state, an energyharvester configured to supply power to the tire pressure sensor module;and wherein the controller is further configured to control an output ofthe information related to the pressure of the tire in the active state,and wherein the controller is configured to operate the tire pressuresensor module in the inactive state based on determining thatinformation related to a velocity of the tire indicates a velocity abovea threshold, wherein the information related to the velocity of the tireis received from the energy harvester.
 2. The tire pressure sensormodule of claim 1, further being configured for valve mounting or beingcomprised in a valve of the tire.
 3. The tire pressure sensor module ofclaim 1, further comprising a battery operably coupled to thecontroller.
 4. The tire pressure sensor module of claim 1, furthercomprising a rechargeable energy device operably coupled to thecontroller and a power interface which is configured to charge therechargeable energy device.
 5. The tire pressure sensor module of claim4, wherein the power interface is configured to be coupled with anothertire pressure sensor module, the other tire pressure sensor module beingconfigured to charge the rechargeable energy device through theinterface.
 6. A tire pressure sensor module, comprising: pressuresensing means for determining information related to a pressure of atire; controller means for selectively operating the tire pressuresensor module in an active state and in an inactive state, wherein anenergy consumption of the tire pressure sensor module is lower in theinactive state than in the active state, energy harvesting means forsupplying power to the tire pressure sensor module; wherein thecontroller means is further for controlling an output of the informationrelated to the pressure of the tire in the active state, wherein thecontroller means is further for operating the tire pressure sensormodule in the inactive state based on determining that informationrelated to a velocity of the tire indicates a velocity above athreshold, and wherein the information related to the velocity of thetire is received from the energy harvesting means.
 7. The tire pressuresensor module of claim 6, further being configured for valve mounting orbeing comprised in a valve of the tire.
 8. The tire pressure sensormodule of claim 6, further comprising a battery operably coupled to thecontroller means.
 9. The tire pressure sensor module of claim 6, furthercomprising a rechargeable energy device operably coupled to thecontroller means and a power interfacing means for charging therechargeable energy device.
 10. The tire pressure sensor module of claim9, wherein the power interfacing means is for coupling with another tirepressure sensor module, the other tire pressure sensor module beingconfigured to charge the rechargeable energy device through theinterfacing means.
 11. A method of operating a tire pressure sensormodule, comprising: determining information related to a pressure of atire using a pressure sensor; selectively operating the tire pressuresensor module in an active state and in an inactive state using acontroller, wherein an energy consumption of the tire pressure sensormodule is lower in the inactive state than in the active state,supplying power to the tire pressure sensor module using an energyharvester; and controlling an output of the information related to thepressure of the tire in the active state using the controller, operatingthe tire pressure sensor module in the inactive state based ondetermining that information related to a velocity of the tire indicatesa velocity above a threshold, wherein the information related to thevelocity of the tire is received from the energy harvester.
 12. Themethod of claim 11, wherein the tire pressure sensor module isconfigured for valve mounting or being comprised in a valve of the tire.13. The method of claim 11, further comprises powering the controllerusing a battery.
 14. The method of claim 11, further comprising:providing a rechargeable energy device operably coupled to thecontroller and a power interface; and charging the rechargeable energydevice through the power interface.
 15. The method of claim 14, whereinthe power interface is configured to be coupled with another tirepressure sensor module, further comprising charging the rechargeableenergy device through the power interface using the other tire pressuresensor module.